Verdict
Claude Fable 5.1 leads 12–3 across 16 shared benchmarks.
Claude Fable 5.1 12 · GPT-6 Sol 3 · 1 tied · higher isn't always better — check the caveats below.
Reported scores — protocols may differ. How we compare
Unknown: Claude Fable 5.1 leads 6–1 across 7 shared unknown benchmarks (largest gap: ProofBench, 100 vs 83 — single evaluator).
Math: GPT-6 Sol leads 1–0 across 2 shared math benchmarks (largest gap: FrontierMath-Tier-4-v2-Private, 90 vs 87.8 — protocols undisclosed).
Reasoning: Claude Fable 5.1 leads 2–0 across 2 shared reasoning benchmarks (largest gap: SimpleQA Verified, 70.8 vs 60.7 — protocols undisclosed).
Claude Fable 5.1 leads 12–3 across 16 shared benchmarks. Claude Fable 5.1 leads 12 benchmarks and GPT-6 Sol leads 3, with 1 tied. Higher isn't always better — see the integrity caveats on each benchmark.
Claude Fable 5.1 and GPT-6 Sol have 16 benchmarks in common in our data — those are the only rows where a direct, apples-to-apples comparison is drawn.
Claude Fable 5.1 leads unknown 6–1. Claude Fable 5.1 leads reasoning 2–0.